Electrosurgical Methods and Devices Employing Phase-Controlled Radiofrequency Energy

ABSTRACT

This disclosure relates generally to electrosurgical methods and devices. In some embodiments, an electrosurgical system/device is provided suitable for applying phase controlled RF energy to a treatment site. The electrosurgical device comprises a multi-electrode electrosurgical probe electrically coupled to a plurality of RF generators. Also provided are methods of use of such an electrosurgical device, as well as other electrosurgical devices. The methods and devices disclosed herein find utility, for example, in the field of medicine.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 12/802,518, filed on Jun. 7, 2010, which claims priority under 35 U.S.C. §119 to U.S. provisional patent application No. 61/213,409, filed Jun. 5, 2009, and U.S. provisional patent application No. 61/213,410, filed Jun. 5, 2009. U.S. patent application Ser. No. 12/802,518 is also a continuation-in-part application of U.S. patent application Ser. No. 11/654,914, filed Jan. 17, 2007, now U.S. Pat. No. 8,206,381, which claims priority under 35 U.S.C. §119 to U.S. provisional patent application No. 60/759,289, filed Jan. 17, 2006, and U.S. provisional patent application No. 60/774,167, filed Feb. 17, 2006. This application therefore also claims priority to U.S. Pat. No. 8,206,381 and each of its priority provisional patent applications. Accordingly, each such noted application is herein incorporated by reference in its entirety.

TECHNICAL FIELD

This disclosure relates generally to electrosurgical methods and devices, as well as electro-treatment methods and devices with respect to cutaneous and sub-cutaneous tissue. The methods and devices disclosed herein find utility, for example, in the field of medicine.

BACKGROUND

Radiofrequency (RF) devices are used to non-specifically and non-selectively ablate or heat different types of tissue. Radiofrequency (RF) devices are typically used to ablate localized skin lesions or to destroy the whole upper surface of the skin. However, whole skin resurfacing methods and devices often times cause burn like post treatment reactions and therefore result in prolonged healing times, increased risk of infections, prolonged erythema, scarring, hyperpigmentation, and hypopigmentation.

To that end, prior art devices do not adequately address skin problems such as, for example, excessive sweating and acne. Moreover, prior art devices are not understood to adequately combine the effects of fat liquefaction, liposuction and skin tightening for the constriction and elimination of enlarged cutaneous and subcutaneous blood vessels, as well as the destruction of benign and malignant tumors.

With regard to excessive sweating, sweating helps the body stay cool. Generally, people sweat more in warm temperatures, during exercise, or in response to situations that make them nervous, angry, embarrassed, or afraid. Nevertheless, excessive sweating may occur without such triggers and cause significant discomfort and embarrassment. When excessive sweating affects the hands, feet, and armpits, the condition is primary or focal hyperhidrosis, which affects 2-3% of the population. If the sweating occurs as a result of another medical condition, it is called secondary hyperhidrosis, which may be all over the body, or in one specific area.

While a few treatments are available to treat severe cases of hyperhidrosis, mostly brachial sympathectomy for the therapy of excessive arm sweating and intradermal botox injection for under arms and palms sweating, such methods have limited effectiveness and often are associated with side effects (sympathectomy) and pain and short term effect (botox). While topically applied anti-perspirants can inhibit excessive sweating in specific areas for periods up to 24 hours, it is usually less effective for use of the palms and soles.

Iontophoresis is a non-invasive method of propelling high concentrations of a charged substance, normally medication or bioactive-agents, transdermally by repulsive electromotive force using a small electrical charge applied to an iontophoretic chamber containing a similarly charged active agent and its vehicle. To clarify, one or two chambers are filled with a solution containing an active ingredient and its solvent, termed the vehicle. The positively charged chamber, termed the cathode will repel a positively charged chemical, while the negatively charged chamber, termed the anode, will repel a negatively charged chemical into the skin. Iontophoresis, the passage of a direct electrical current onto the skin, is a long-established therapy for hyperhidrosis. Since its introduction in 1952, iontophoresis has proved to be a short term relatively effective treatment that is suitable for patients to use at home.

Various agents have been used in conjunction with iontophoresis, including tap water, salt water, and anti-cholinergic drugs. Iontophoresis with saline is less effective than tap-water iontophoresis. Successful induction of hyperhidrosis by tap-water iontophoresis requires the application of 15 to 20 mA to each palm or sole for 30 minutes per session for 10 consecutive days, followed by one or two maintenance sessions per week. Initially, many patients experience an aggravation of their symptoms, but this problem resolves after three to five treatments. Without maintenance therapy, symptoms recur in one to two weeks.

Use of combined aluminum chloride, an anti-cholinergic drug, and tap-water iontophoresis for one hour each day resulted in the remission of symptoms for 20 days, compared with 3.5 days for the use of iontophoresis alone; this combination also was more effective in reducing the severity of symptoms. Although this apparatus is effective for short term inhibition of sweating it is cumbersome to use and requires multiple treatment to induce effect and many more treatment to maintain sweating inhibition.

With regard to acne, acne is a disorder caused by a series of events, among them overproduction of sebum in the sebaceous glands, obstruction of glands orifice, proliferation of p.acnes bacteria in the enlarged gland and skin inflammation. There are multiple of partially effective treatments for acne including topical anti bacteria agents, oral antibiotics and blue light phototherapy. The only treatment that has a suppressive effect on the sebum production is isotretinoin. Unfortunately, however, the use of isotretinoin is limited due to multiple and significant side effects.

Accordingly, there is a clear need for a method and device that will be more effective and provide results faster and for longer periods for effective treatments of excessive function of skin glands, for in-clinic use by medical professionals. In addition, there is also a need for a hand held embodiment of the method and apparatus to be easily self-applied for home use.

Radiofrequency (RF) devices are also used to ablate or heat in a non- specific and non-selective way different types of tissue. In surgery, RF devices are generally used to ablate localized lesions or to coagulate bleeding blood vessels. In dermatology, RF devices use bipolar electrodes to increase the heat of dermal skin layers through the creation of electrical current flowing in parallel to the skin surface. Other RF devices use mono or unipolar electrical energy for the heating of the deep layers of skin. Since the energy produced by a monopolar device flow between the small electrode inserted into the tissue and a large electrode attached to the skin, they are not suitable for homogenous and symmetric thermally treated volume of tissue.

Since prior art devices are limited in their functionality to address the noted problems outlined above, there is a clear need for a method and apparatus that would allow symmetric, homogenous and deep heating for disruption and destruction of subcutaneous or internal tissues and tumors. In addition, there is a clear need for a method and apparatus that would allow symmetric, homogenous and deep heating for disruption and destruction of subcutaneous or internal tissues and tumors. Current RF devices lack the ability to control the spatial direction, energies and nature of electrical energies affecting the treated area and thus lack the desired selectivity and specificity needed for each of the specific therapeutic indications.

Despite advancements in the use of optical and RF devices for treating biological tissue, there continues to be a need in the art to develop effective electrosurgical devices, treatments and methods that are suitable for treating a wide variety of conditions.

SUMMARY OF THE DISCLOSURE

The present disclosure is directed at addressing one or more of the abovementioned drawbacks of known electrosurgical methods and devices.

Some embodiments of the present disclosure relates generally to the field of electro surgery, and more particularly to surgical devices and methods which employ high frequency phase controlled electrical energy to treat a patient's body, including but not limited to dermatological disorders such as excessive sweating and excessive production of sebum through the sebaceous glands.

Since monopolar radiofrequency devices deliver energy from one surface electrode uncontrolled through the whole body to a plate electrode and/or simple bipolar or multipolar devices, radiofrequency energy flows relatively superficially and mostly in parallel to the skin surface these methods are not optimal for the directional and deep but spatially contained energy.

Accordingly, phase controlled radiofrequency methods and devices according to some embodiments disclosed herein allow deep delivery of RF energy, perpendicular to the skin surface, thereby heating the ducts and glands to suppress functionality thereof for the treatment of target medical or aesthetic disorders. In addition to thermal effects, some embodiments allow introduction of a therapeutic compound(s) in the appropriate direction and depth required to reach target areas without the side effects related to other methods and apparatus of existing electrosurgical devices.

In some embodiments, due to differences in impedance between sweat and surrounding tissue, and/or sebum and surrounding tissue, the delivered phase controlled energy delivered to the target tissue is expected to concentrate up to four times (for example) in the inner lumen of the seat ducts and glands and on the outer walls of the sebaceous glands.

In some embodiments, due to decreased energy flow on the skin surface, the perpendicular direction of energy flow and the locally contained energy, an effective therapy with lowered risk for side effects is provided.

In some embodiments, systems, methods and devices are presented which employ high frequency electrical energy to treat a patient's body, including but not limited to dermatological disorders for which the following treatments may be applicable—such as, for example, subcutaneous fat liquefaction and skin tightening, destruction of varicose veins, and/or other surgical procedures that require the destruction of internal and external benign and malignant tumors or therapy of tissue hypertrophies such as benign prostate hypertrophy.

In some embodiments, using phase controlled RF systems, devices and methods lead to effective therapy with a reduced risk for side effects and reduced healing times due to, for example, minimized and/or controlled treatment which lead to more specific therapeutic effects.

For example, in some embodiments of the disclosure, phase controlled RF technology may be used to treat one of multiple medical and aesthetic skin disorders, including but not limited to dermatological disorders such as excessive sweating and excessive production of sebum through the sebaceous glands.

In some embodiments, phase controlled RF treatment may be done after injection of tumescent local anesthetic to the treatment area. Moreover, in some embodiments, the phase controlled RF treatment may be the sole treatment for the manipulation of function or destruction of the treated skin glands.

In some embodiments, phase controlled RF treatment may be combined with application of a coupling solution such as a water based treatment gel, tap water or baby oil (for example).

In some embodiments, the phase controlled RF treatment may be combined with the application of a treatment compound with anti-perspirant activity such as, but not limited to, aluminum hexhydrate.

In some embodiments, the phase controlled RF treatment may be combined with the application of a treatment compound with anti-acne or anti-seborrheic activity such as, but not limited to, salicylic acid and/or benzyl peroxide.

In some embodiments, the cannula with the phase control electrodes, may be cooled by an active TEC (“thermo-electrical cooling”) module or by passive means such as a freezer cooled “ice pack”, for example.

In some embodiments the phase controlled RF treatment may be constructed as a hand held self treatment home use device.

In some embodiments, an electrosurgical treatment system is provided and may include a plurality of RF sources, where the sources are phase controlled and arranged to establish an impedance between the sources (Z2) is larger than the impedance load (Z1) of the source.

BRIEF DESCRIPTION OF THE DRAWINGS

This patent application contains at least one drawing executed in color. Copies of this patent application publication (or issued patent) with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 illustrates a system according to some embodiments of the present disclosure, directed to a configuration of two pairs of phase controlled RF sources.

FIG. 2 illustrates a system according to some embodiments of the present disclosure, which includes a system control unit, an RF generator, two or more phase shifter modules, and a treatment tip.

FIGS. 3A and 3B illustrate comparative color photographs of treated and untreated underarms of patients with primary or focal hyperhidrosis,

FIG. 4 illustrate an exemplary system according to some embodiments of the present disclosure, including a thermal camera, a bowl with liquid egg protein and a cannula having electrodes according to some embodiments of the subject disclosure.

FIGS. 5-6 are color images illustrating temperature changes surrounding a cannula as related to heating by a system according to some embodiments of the present disclosure.

FIG. 7A is a color figure which illustrates an exemplary system according to some embodiments of the present disclosure, as well as illustrates current flow in a system with three (3) RF generators.

FIGS. 7B-7D are color figures illustrating various analysis of the system of FIG. 7A, regarding current density.

DETAILED DESCRIPTION

Before describing embodiments of the present invention in detail, it is to be understood that unless otherwise indicated, this invention is not limited to particular electrosurgical methods, electrosurgical devices, or power sources, as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

It must be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, “a power source” refers not only to a single power source but also to a combination of two or more power sources; “an electrode” refers to a combination of electrodes as well as to a single electrode, and the like.

Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art to which the invention pertains. Although any methods and materials similar or equivalent to those described herein may be useful in the practice or testing of the present invention, preferred methods and materials are described below. Specific terminology of particular importance to the description in the present disclosure is defined below.

As used herein, the terms “may,” “optional,” “optionally,” or “may optionally” mean that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not.

As used herein, the term “device” is meant to refer to any and all components of a system. For example, an “electrosurgical device” refers to an electrosurgical system that may comprise components such as electrosurgical probes, power sources, connecting cables, and other components.

The terms “treating” and “treatment” as used herein refer to reduction in severity and/or frequency of symptoms, elimination of symptoms and/or underlying cause, prevention of the occurrence of symptoms and/or their underlying cause (e.g., prophylactic therapy), and improvement or remediation of damage.

By “patient” or “subject” is meant any animal for which treatment is desirable. Patients may be mammals, and typically, as used herein, a patient is a human individual.

The terms “light” and “light energy” as used herein are meant to include visible, infrared, and ultraviolet electromagnetic energy.

The term “phase” as used herein refers to the phase angle of an alternating-current (AC) radiofrequency (RF) voltage (sometimes referred to as an “RF signal” or “RF voltage”). In some cases, the term “phase” also refers to the phase angle difference between two RF voltages. Accordingly, the term “phased RF energy” refers to RF energy that comprises at least two component RF voltages, wherein each component RF voltage independently has a phase.

It is worth noting that at least some of the embodiments of the disclosure of parent application Ser. No. 11/654,914 (U.S. publication no. 2007-0191827), which is incorporated by reference herein, can be incorporated and/or otherwise used in and/or for some of the embodiments directed toward treatments for excessive sweating and acne, as well as in skin contour treatments. Accordingly, in some embodiments of the subject application, one or more RF sources are used to generate an electrical field (F) or fields in, but not limited to, the skin and/or subcutaneous area, while the form and area of the electrical field or fields is controlled by the relative phase (p) between the RF (R) source or sources and the electrical parameters of each RF source or sources. The polarity of this electrical field (F) may vary in time according with the RF sources setting. These variations will attract and repel and consequently move free electrons or ions heating the treated area, according to some embodiments of the present disclosure.

FIG. 1 illustrates a system according to some embodiments of the present disclosure, which is directed to a configuration of two pairs of phase controlled RF sources that generate one or more, and preferably, a plurality of electrical fields in the treated tissue. The intensity, form and area of the electrical field or fields are controlled by the relative phase (φ) between the RF source or sources and the electrical parameters of each RF source or sources. The polarity of this electrical field (F) will vary in time according with the RF sources setting. These variations attract and repel free electrons or/and ions, consequently moving them, thereby heating the treated area.

FIG. 2 illustrates a system according to some embodiments of the present disclosure, which includes a system control unit, an RF generator, two or more phase shifter modules (1, 2), and a treatment tip. The treatment tip is used to contact tissue. The system control unit may be used to control and/or generate the necessary energy applied by the treatment tip. The system may also incorporate either or both of a cooler unit and a microcontroller. The micro-controller may be used to control diagnostics (e.g., in real-time) such as skin temperature and skin impedance (for example). The system may also incorporate a compound container dispensing a liquid and/or gel during therapy.

FIGS. 3A and 3B illustrate comparative photographs of treated and untreated underarms of patients with primary or focal hyperhidrosis, this preliminary pilot test was performed to test the feasibility of sweat reduction using multi-source phase control radiofrequency. Accordingly, two patients with hyperhidrosis were treated, in which in each patient, one armpit was treated and one armpit was left untreated (i.e., control side). The treatment included the delivery of heat using a prototype device according to at least some embodiments of the present disclosure (phase controlled RF). Starch tests were performed before and after treatment.

As illustrated, the results verified clear reduction of sweat production in the treated areas as compared to untreated areas.

FIG. 4 is a photograph of a system set up to perform a feasibility test for some embodiments of the present disclosure. This figure illustrates the test setting. The basic device may be comprised of a cannula (e.g., 57 mm length, diameter 6 mm) attached to a plastic handle. On the cannula, 6 ring electrodes (3 mm width each) are included in two groups of 3 electrodes. The distance between the electrodes in the group in the embodiment illustrates are 3 mm and between the two groups 9 mm. Each electrode preferably is attached to an independent, phase controlled RF source according to one or more of the embodiments disclosed herein. Half of the cannula is immersed in a tank filled with liquid egg protein, RF was delivered to the device and thermal images were captured.

FIGS. 5-6 are color images which illustrate frames from a video of the test, illustrating the temperature changes during the test. FIG. 5 illustrates a laboratory thermal study with a system according to some embodiments of the disclosure. The prototype was connected to six (6) phase controlled RF generators, for a total power of 15 W. Each generator was connected to a separate ring electrode. The system was immersed in a container filled with liquid egg protein. Thermal video imaging (the figure) illustrate gradual heating of the surrounding liquid egg protein forming a cylinder of heat around the active area.

FIG. 6 illustrates a laboratory thermal study with a system according to some embodiments of the present disclosure. As shown, the thermal images show, at a radius of 6 mm, a delta of heat of 40 deg Celsius and a delta of temperature of 20 deg Celsius at 20 mm radius.

Accordingly, the feasibility test used multiple sources, phase control radiofrequency for volumetric three dimensional heating as described in some of the embodiments disclosed herein. Methods and settings: a cannula was inserted in a container filled with liquid egg whites (i.e., protein—simulating biological tissue). Multi-source phase control radiofrequency was delivered through the prototype yielding the following results.

A change in temperature (ΔT) due to heating of approximately 40° C. was achieved to a radius of 6 mm. In addition, a change in temperature (AT) due to heating of approximately 20° C. was achieved to a radius of 20 mm. As a result, the prototype was able to heat in a three dimensional, volumetric fashion in a controlled way to a significant radius around the cannula.

FIG. 7 illustrates an exemplary system according to some embodiments of the present disclosure, as well as illustrates current flow in a system with three (3) RF generators. FIG. 7 aids in illustrating a scheme according to some embodiments of the disclosure that heats skin/tissue more homogenously than mono or bi-polar configuration. Such a scheme is, according to some embodiments, is based on two facts: (1) the RF sources are phased controlled, and (2) the geometry of the electrodes and/or the placement of the electrodes relative the surface of the skin defines different impedances between the electrodes.

For example, with reference to FIG. 7A, defining electrodes from Left to right: 701, 702, 703, 704, 705 and 706. Electrodes 701 and 702 are driven by RF generator #1, electrodes 703 and 704 are driven by RF generator #2 and electrodes 705 and 706 are driven by RF generator #3. FIG. 7B illustrates current density when a single pair of bipolar electrodes is used. In such a case, one single current flows from one electrode to another and the current density is mostly in the surface of the skin and decreasing with depth of the skin.

FIG. 7C illustrates current density with two bipolar electrodes, but without significant relation (high impedance) between the two RF generators. In this case, the result is similar to the previous analysis/illustration (FIG. 7B), in that there is significant gradient between the surface and below the skin.

FIG. 7D illustrates current density when the distance between the sources becomes small enough that the impedance load to each RF source becomes bigger than the impedance between sources (i.e., electrodes 702 and 703 are closer than electrodes 703 and 704) and the RF sources are phase controlled, homogenous heating is generated.

According to the above example illustrated by FIGS. 7A-7D, a system with more than one (1) RF source, where the sources are phase controlled and the electrodes are arranged to establish an impedance between the sources (Z2) is larger than the impedance load (Z1). See FIG. 7D. In some embodiments, the impedance between sources (Z2) is in the range of between about +/−100% than the impedance load (Z1) of the source.

All patents, patent applications, and publications mentioned herein are hereby incorporated by reference in their entireties. However, where a patent, patent application, or publication containing express definitions is incorporated by reference, those express definitions should be understood to apply to the incorporated patent, patent application, or publication in which they are found, and not to the remainder of the text of this application, in particular the claims of this application.

It is to be understood that while the invention has been described in conjunction with the preferred specific embodiments thereof, that the foregoing description as well as the examples that follow, are intended to illustrate and not limit the scope of the invention. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention, and further that other aspects, advantages and modifications will be apparent to those skilled in the art to which the invention pertains.

Other embodiments of the present disclosure may include controllers which include processors, a CPU(s), a MCU(s), a memory device and/or a plurality of such components. The processor device(s) may further include peripheral devices to enable input/output functionality. Alternatively and/or additionally, in some embodiments, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit) may be used in the implementation of the processor device(s). Still other embodiments may be directed to computer readable media (e.g., flash memory, CD, DVD, and the like) which contain application programs and/or computer instructions for carrying out processes according to certain method embodiments disclosed herein.

Any and all references to publications or other documents, including but not limited to, patents, patent applications, articles, books, etc., presented in the present application, are herein incorporated by reference in their entirety.

Although a few variations have been described in detail above, other modifications are possible. For example, the logic flows disclosed either expressly or implicitly herein do not require the particular order shown, or sequential order, to achieve desirable results.

Although particular embodiments have been disclosed herein in detail, this has been done by way of example for purposes of illustration only, and is not intended to be limiting with respect to the scope of the appended claims, which follow. In particular, it is contemplated that various substitutions, alterations, and modifications may be made without departing from the spirit and scope of the invention as defined by the claims. Other aspects, advantages, and modifications are considered to be within the scope of the following claims. The claims presented are representative of the embodiments and features disclosed herein. Other unclaimed embodiments and features are also contemplated. Accordingly, other embodiments are within the scope of the following claims. 

What is claimed is:
 1. A method for delivering energy to a target site of a patient comprising placing a cannula within close proximity of the target site and delivering phase controlled RF energy to the cannula.
 2. The method of claim 1, wherein the target site is tissue, the cannula includes one or more electrode pairs and the energy increases the temperature of the tissue in the region of tissue adjacent the cannula.
 3. The method of claim 1, wherein the cannula contacts the target site.
 4. The method of claim 1, wherein the cannula creates an electric field having properties that are determined at least in part by the phase between a first electrode pair on the cannula and a second electrode pair on the cannula.
 5. The method of claim 4, further comprising at least one of the following: actively adjusting the phase between the first electrode pair and the second electrode pair while the cannula is in close proximity to the target site, actively adjusting the phase controlled RF energy to the cannula in response to a measured parameter of the target site, applying topical anesthetic to the target site, applying a liquid or gas to the target site to regulate the temperature of the target site, applying a conductive liquid or gel between the cannula and the target site, applying light energy to the target site, applying ultrasound energy to the target site, or any combination thereof.
 6. The method of claim 5, wherein the target site is living tissue and the measured parameter is the impedance of the tissue.
 7. The method of claim 4, wherein the phase between the first electrode pair and the second electrode pair is held constant while the cannula is in close proximity to the target site.
 8. The method of claim 4, wherein the phase between the first electrode pair and the second electrode pair is varied while the cannula is in close proximity to the target site.
 9. The method of claim 1, wherein the target site is a sweat gland, a sebaceous gland or a combination thereof
 10. The method of claim 9, wherein the phase controlled RF energy delivered to the cannula increases the temperature of the gland.
 11. The method of claim 3, wherein the target site is skin, and wherein the phase controlled RF energy non-homogeneously increases the temperature of the tissue adjacent the cannula.
 12. The method of claim 1, wherein cannula includes two or more cylindrical electrodes arranged substantially in line such that heat is generated in a three (3) dimensional form from an external side of a first electrode to the external side of a second electrode.
 13. The method of claim 1, wherein the cannula is a single-use cannula.
 14. The method of claim 1, wherein the cannula includes a plurality of ring electrodes arranged in one or more groups of electrodes.
 15. The method of claim 14, wherein the plurality of ring electrodes are arranged two or more groups of electrodes each having one or more electrodes.
 16. The method of claim 14, wherein the groups of electrodes are predetermined distance apart from each other.
 17. The method of claim 1, the method further comprising treating cutaneous and/or sub-cutaneous tissue for the treatment of subcutaneous fat liquefaction, skin tightening, vascular disease, and varicose veins.
 18. An electrosurgical system comprising: (a) a cannula for applying at least a heat treatment to tissue of a patient, the cannula being configured with a plurality of electrodes arranged substantially in line, the plurality of electrodes including at least a first electrode, a second electrode and a third electrode; and (b) one or more RF generators comprising a plurality of outputs and phase shifting circuitry for controlling the phase between the plurality of outputs, wherein the connection between the plurality of outputs and the plurality of electrodes is configured such that at least one electrode pairing is formed, the at least one electrode pairing including a first electrode pair comprising the first electrode and the second electrode, the first electrode and third electrode or the second electrode and third electrode, wherein the phase shifting circuitry is configured such that the plurality of outputs apply a respective RF electrical potential across the at least one electrode pairing, and wherein the RF electrical potential across the at least one electrode pairing causes heating of the tissue of the patient.
 19. The electrosurgical system of claim 18, wherein any two of the plurality of electrodes may be electrically coupled to any of the plurality of outputs of the one or more RF generators.
 20. The electrosurgical system of claim 18, wherein the at least a heat treatment includes delivering RF energy to the cannula.
 21. The electrosurgical system of claim 18, wherein the tissue includes a sweat gland, a sebaceous gland or a combination thereof.
 22. The electrosurgical system of claim 21, wherein the phase controlled RF energy delivered to the cannula increases the temperature of the gland.
 23. The electrosurgical system of claim 18, further comprising at least one of: means for applying light energy to one or more sweat glands or sebaceous glands of the patient, means for applying ultrasound energy to one or more sweat glands or sebaceous glands of the patient, means for applying a temperature-regulating liquid or gas to one or more sweat glands or sebaceous glands of the patient, means for adjusting the RF power delivered by one or more of the plurality of RF outputs in response to a measured parameter.
 24. The electrosurgical system of claim 23, wherein the measured parameter is the electrical impedance of tissue of the patient.
 25. The electrosurgical system of claim 18, wherein the system is further arranged to deliver a therapeutic compound to one or more sweat glands or sebaceous glands of the patient.
 26. The electrosurgical system of claim 18, wherein RF energy is applied by the cannula to the tissue of the patient after tumescent local anesthetic has been injected into the tissue.
 27. The electrosurgical system of claim 18, wherein RF energy is applied by the cannula to the tissue of the patient in combination with at least one of a (i) coupling solution, (ii) water-based treatment gel, tap water or baby oil, (iii) a treatment compound having anti-perspirant activity or (iv) a treatment compound having anti-acne or anti-seborrhoeic activity.
 28. The electrosurgical system of claim 27, wherein the treatment compound having anti-perspirant activity is aluminum hexhydrate.
 29. The electrosurgical system of claim 27, wherein the treatment compound having anti-acne or anti-seborrhoeic activity is selected from the group consisting of salicylic acid and benzyl peroxide. 